Woven wire belt for fourdrinier machines



Aug. 11, 1942. w. c. SUTTON 2,292,411

-WOVEN WIRE BELT FOR FOURDRINIER MACHINES OriQinal Filed Sept. 21, 1939 INVENTORY BQM W2 m4 Patented Aug. 11, 1942 sates E ATENT E EICE WOVEN WIRE BELT FOR FOURDRINIER MACHINES Vi! alter 0. Sutton,

to The Lindsay Wire Weaving Company,

Shaker Heights, Ohio, assignor Cleveland, Ohio, a corporation of Ohio Original application September 21, 1939, Serial No. 295,993, now

Patent No. 2,221,696, dated November 12, 1940. Divided and this application July 17, 1940, Serial No. 345,964

11 Claims.

This invention relates to a new article of manufacture in the form of a woven wire belt having special characteristics making it particularly suitable for use in a Fourdrinier machine. The present application is a division of my copending application Serial No. 295,993, filed September 21, 1929, (now Patent No. 2,221,696, issued November 12, 1940) for Paper making fabric and method and apparatus for making the same. That application is now restricted to the apparatus, while another division thereof relates to the method of making the woven wire belt herein shown, described and claimed as an article.

Firmness is an essential quality in the Fourdrinier wire belt. Sleaziness or looseness of the fabric tends to cause wrinkling and shorter operating life. Twill weave fabric is more susceptible to sleaziness than the older plain weave wire cloth, although it has other advantages, as outlined below, which make it valuable for many machines.

One of the advantages of twill weave over plain weave is the fact that more wearing surface is available on that side of the belt which is subject to the abrasive action of the suction boxes. In twill weave, each warp wire passes over one weft wire, and under two weft wires in succession, but so far as I am aware, no one has been able to so weave a twill fabric that the underlying portion of the warp wires extend parallel to the plane of the top surface on the suction boxes; instead, the under portion of each warp wire has extended at an angle to the surface of the suction box and consequently has formed a knuckle which takes the initial wear. The area of the knuckle so formed is considerably smaller than the area of the entire underlying portion of each warp wire and hence the wear is concentrated, and the warp wires have been worn through prematurely.

The disadvantage of the twill weave, however, is the fact that a paper web formed on the twill is marked more than that formed on a plain weave, because the weft knuckles are more widely spaced and do not rise to the plane of the top of the warp knuckles in the normal weaving operation; but the co-planar relationship of the warp and weft knuckles has been improved by beating up the weft wires to a greater degree. Such action has increased the pressure against the warp wires, accentuating the angularity of the underlying portions of the warp wires, so that a gain in smoothness on the top surface of the belt has been commensurate with a loss in available wearing surface on the bottom of the belt.

The primary object of my invention is to provide a woven wire belt of a fabric which is firmer and more compact than that obtained merely from a weaving operation, and which will therefore possess greater mechanical strength and resistance to fracture from successive bending in reverse directions.

An additional object is to make a fabric which, when woven as a twill weave, will have the top of the warp and weft knuckles in the same plane and will have the underlying portions of the warp wires disposed for substantially their entire length parallel to the plane in which the topmost surfaces of the belt lie, and therefore parallel to the plane of the wearing surface of the suction boxes.

My fabric though composed of woven warp and weft wires is flat for considerable regions of the wires on the upper and under surface, such action being effected by pressure applied to the fabric after it is woven. Such flattening or leveling of the fabric as a whole improves its performance on both the upper and under surface, as it makes a more substantial support for the paper and causes less abrasion of the suction boxes.

My belt is first formed as a web of fabric; then the ends are joined together in a seam to make an endless belt; thereafter the fabric proper and its seam are flattened by pressure.

My improved belt is illustrated in the drawing hereof, and is hereinafter described in detail, and its essential novel features set out in the claims.

In the drawing, Fig. l is a plan of my belt, the same being shown as mounted on a pair of rollers; Fig. 2 is a section much enlarged; Fig. 3 is a corresponding section of the woven fabric before it is treated to produce my flattened belt; Fig. 4 is a diagrammatic elevation illustrating the belt passing around a roller and flattened by a comparatively small roller pressing against it.

In Fig. 1, I have shown, at A, the belt as an endless member looped about a pair of rollers B and B The ends of the original fabric composing the belt are joined together at a by a suitable seam made in any approved manner.

The belt is composed of warp wires and weft wires woven in a twill weave so that each wire passes first over one wire transverse thereof, and then under two wires in succession, or under one wire then over two wires in succession, as will be readily understood.

Fig. 3 indicates on a greatly enlarged scale, an accurate reproduction of a section taken lengthwise through a twill woven fabric composed of warp wires l and weft wires II, this view indicating the fabric before flattening treatment to produce my improved flattened fabric. By my invention, after such a fabric as is shown in Fig. 3 is produced, it is submitted to pressure so that both the weft and warp wires are flattened on their exposed regions. Thus, in Fig. 2, I have disclosed the warp wire Illa flattened at l2 on the upper face of the fabric, and weft wires I l-a flattened at I3 on the upper face, the plane to which the wires are flattened being defined by secants of the normal curvature of the knuckles.

It will be seen from inspection of Fig. 3, illustrating a normal twill woven fabric, that the weft wires are all below the top plane and above the bottom planes tangent to the warp knuckles, whereas in Fig. 2, illustrating my fabric in its final condition, the topmost and bottommost regions of weft wires are respectively in the same plane as the top and bottom knuckles of the warp wires.

As set out in my parent application, I find I can accomplish the desired result very satisfactorily by placing the belt A about stretching rolls B and B and then as the belt travels due to the rota- .tion of the rolls, I flatten it by pressure against a narrow region of the exposed surface of the belt where the opposite surface is supported by one of the rolls.

As shown in Fig. 4, I have indicated a comparatively small roll 0 extending across the belt parallel with the roll B, and this small roll is submitted to a substantially uniform pressure continuously as the belt travels past the roll in the rotation of the roll B. By pressing only a comparatively small region of the belt at any one time, I am enabled to flatten it effectively, as set out in my parent application.

It i preferable for the cloth to make two or more successive passes under the pressure roll. In fact, the pressing operation may continue until each region of the belt has travelled a number of times past the pressing roll, which gradually compresses the web uniformly across the belt until the resultant web has a uniform thickness and all of the knuckles come to the bounding .top and bottom planes.

I have found that in order to secure the maximum firmness in the cloth after rolling, it is desirable to pass it through the rolls in the direction opposite to that in which it was woven. This forces the weft wires against the steeper end of the warp crimps and locks the two firmly together.

Such a belt as described more effectively supports the paper being formed by reason of the long flat surfaces of the warp and Weft wires than can be accomplished by the usual knuckles to which the paper is only tangent. Another advantage of my belt is that the long hat knuckles on the underside cause less wear to the suction box than the more abrupt knuckles of the ordinary woven belt.

The known advantage which twill weave possesses over an ordinary weave for a belt in a Fourdrinier machine is therefore further increased on bO'L-h sides of the belt, and this increased advantage is accomplished without reducing the strength of the belt or interfering with its flexure as it passes about the rolls at the two ends of the belt.

I claim:

1. A wire web for a Fourdrinier machine belt both sides, and flattened on one side more than the other by distortion of the wires.

2. A wire cloth of twill weave in which the crests of the warp and weft knuckles on the underside of the belt touch the same boundary plane and in which the warp and weft knuckles on the upper side of the belt touch the same boundary plane, the warp and weft wires being flattened on the upper side of the belt to a greater degree than they are on the lower side.

3. An endless belt of wire cloth composed of the web havin its ends joined together by a scam, the web and seam being uniformly flattened to the same thickness.

4. An endless belt of cloth woven of round warp I and weft wires with the ends joined together by woven of round wires, said Web being planular on a seam, the body of the cloth and the seam being uniformly flattened to give the same thickness, which thickness is less than the sum of the diameters of a warp wire and a weft wire.

5. A paper machine wire cloth of twill weave as prepared for use, made of normally round wires, the knuckles of said wires at the bottom of the cloth, both as to the warp and the weft, being tangent to the same plane, and in which the contacting surfaces of crossing wires are comprised of circular arcs, and in which, on the upper face of the cloth, the warp and weft knuckles are deformed by flattening, so that the total thickness of the cloth is less than the sum of the thickness of a warp wire and a weft wire.

6. Paper machine wire cloth of twill weave with pairs of wires alternating with a single wire in both the warp and weft, and the lon warp knuckles are substantially straight and parallel to the plane of the cloth from center to center of adjacent weft wires and in which the short Warp and weft knuckles are deformed by flattening without removal of material so that the total thickness of the cloth is less than the sum of the normal thicknesses of a warp wire and a weft wire.

7. Paper machine wire cloth of twill weave as prepared for use, with pairs of wires alternating with a single wire in both the warp and weft, and in which the long warp knuckles are substantially straight and parallel to the plane of the cloth from center to center of adjacent wef t wires, and in which the exposed face of the short knuckles is flattened on the upper side so that the total thickness of cloth is less than the sum of the thicknesses of a warp and a weft wire.

8. Paper machine wire cloth of twill weave of round wires, in which the long weft knuckles are substantially straight and parallel to the plane of the cloth from center to center of adjacent warp wires, in which the short knuckles are flat on top and round at the bottom and in which the total thickness of cloth is less than the sum of the thicknesses of a weft wire and a warp wire.

9. Wire cloth of twill weave with pairs of solid wires alternating with a single solid wire in both the warp and weft, and in which the weft wire is round and of greater thickness than the warp wire which is also round, said wires being uninterrupted where they cross each other and in which the long warp knuckles are substantially straight and parallel to the plane of the cloth from center to center of adjacent weft Wires on one side of the cloth and the short knuckles on the opposite side are flattened and the cloth has a total thickness less than the sum of the thickness of a warp and a weft wire.

10. Wire cloth of twill weave in which the plane defining the bottom of the cloth is substantially a tangent to all of the warp and weft knuckles at the bottom and in which the plane defining the top of the cloth is a secant with reference to the normal curvature of the warp and weft knuckles.

11. Wire cloth of twill weave in which the weft wire is of greater thickness than the warp wire and in which the long warp knuckles and the long weft knuckles are substantially straight from center to center of the adjacent wires transverse thereto, all of the warp and weft knuckles at the bottom of the cloth being substantially tangent to the one plane and all of the warp and weft knuckles at the top of the cloth touching one plane which is a secant with reference to the normal curvature of such top knuckles.

WALTER C. SUTTON. 

